Domestic appliance



Nov. 11, 1958 G. B. LONG 2,860,026

DOMESTIC APPLIANCE Filed March 8, 1956 2 Sheets-Sheet l 5 i5 as IN V EN TOR.

BY Gear 5. L019 I5! 73 15/ ms mower 3, 2 DOMESTIC APPLIANCE C eorgeh. Long pDayton, Ohio, assignor to General Motors Corporation, Detroit, Micln, a corporation ,l s 1 Application March 8, 1956, Serial No. 570,317 7'cisims. (Cl. 312-296) aqThis invention relates to a-domesticgappliance and more particularly.todouble doors for electronic ovens and other compartments. ,1 if 1 .ln electronicovens, itis essential to -preventarcing'between metal surfaces in the field of electromagneticwaves and :also to prevent the escape of electromagnetic waves from the oven. This is particularly a problem when double doors are provided for closing the oven compartmdlt, .s 'It is an object of this invention tofprovide a wall type oven with double doors making a tight metal to metal seal with'each other and with the wallsof the oven-for preventing arcing and the escapingof electromagnetic waves. it is another object of this invention to provide a wall type oven with double doorsin which the -meetingfaces of the doors are always properly aligned in closed p iti A a :l HT. 1. Theseandother objects are attained 'in the form shown in the drawings in which thewall type oven is provided with a magnetron tube cooled by a blowerlwhich also rotates the .mode stirrer in the top of the oven. An electric fan draws air from the room around the. magnetron tube andthe wave guide'and the electronic apparatus, and

returns the warmed airto the room. The oven is provided with double doors having inner; movable panels which'are slidably mounted in a lateraldirectionp; When the doors are closed one set of springs urges bothinner panels tightly against the portion of the walls surrounding the front opening to the even while a second set of springs urges the panels together attheir adjacentedges. In one form of the invention movable handles are pro: vided, either of which will move. the oneinnerpanel toward the hinges and hold it in that position until the dooriis reclosed to insure thatbothnpanelsrwill be held tightly against the portion of the wallsurrounding the opening of the oven compartment before the panels move into' contact with'each other.- J" a: a." i: 1 In-"another form the meeting edges of the-panels are provided with'matching abutting surfaces toassurethe alignment of the inner faces ,of the panels whenthe doors are. closed so that both panels 'willibe held by the springs in reasonable tightengagementwith the portion of the wall seal at the opening to the oven compartment. rFurther objects and advantagesofthe present invention will :beapparentfro-m the following description; reference being had: to the accompanying drawings,;wher ein"a preferred form of the present invention is clearly shown.

'In.the drawings: a I Figure 1 is a vertical sectionalview through a wall type ovenprovided with double'doors embodying one form of'jmy invention; 7 p l Figure 2 is a rear view of the doors shown in Fig- UH .r r31 all 7. .l 4.7 a, .Jv. figu e? le ,fr sm ery. eason .YiFFY of the doors tak n am s h .line,. \.,3. of Figu es La d; Figure 4 is a fragmentary sectional view similar to Figure 3 with the doors shown partly open; and

..c WV 'ntdNo 11, 195

Fignre 5 is a fragmentary sectional view similar to Figure Shut showing a modified form of the panel matching arrangement. I I

Referring now to the drawings and particularly to Figure 1, there is shown an electronic oven arrangement 20 mounted in a vertical wall 22. This electronic oven arrangement 20 includes anouter casing formed of top, bottom, side and rear walls 24. Within this casing 24 is mounted an oven liner 26 immediately enclosing the electronic oven compartment 28. The space between the casing 24 and the oven liner 26 provides a passageway 30 containing an electronic apparatus 32 which provides a suitable supply of energy to the magnetron tube 34 cooled by theblower 36 driven by the electric motor 38. The shaftof the motor 38is also provided with a pulley 40 which through a belt 42 and a second pulley 44 drives the mode stirrer 46 within the top of the oven compartment28. Beneath the stirrer 46 is a sheet of quartz 48 or similar materialwhich will pass electromagnetic waves and withstand heat. This sheet 48 shields the stirrer 46 from thetsputtering ofthe grease during broiling.

The magnetron tube 34 delivers electromagnetic waves through the wave guide 50 through an opening 52 in the topof the oven compartment28. ,These electromagnetic waves areuniforrnly distributed throughout the compartment 28 by the stirrer 46. The apparatus is further cooled by; an electric motor d iven fan 54,which draws in airlthrough the upper inlet 5 6 into the passage 30 into heat exchangerrelationwithmagnetron tube 34 and the electronic apparatus32 and discharges the air through {a louver. or grille- 58 vlocated inthe front end of the lower leg of passage filmbeneath the double doors 60 and ,62 The oven compartment may be provided with a resistance heater 64 for broiling and browning certain food. Suitable. screened openingsr 66 in th e liner and 68 and 70 in the. doors 60 and 62; are provided, These openings 66, 68 and 70 have screens of sufiiciently small mesh;to prevent the escape of electromagnetic waves but permit the escape of vapors and fumes, and permit viewing the food load o d-7") Tit; i V

.7 As showniin Figure 2't e doors 60 ,and 62 on their inner-faceare provided vvith; inturned -flanges 72 and 74 upon. the top and.bottom and-thehinged edges, These flanges 72 and 74 limit the inward m ovement of the inner panels 76. and 78-as well, est-he movement of the panels 76 and 78toward the hinges 80: As best shown in Figures 3.and.4 the panels 7 6and 78 of thin flexible metal are .resiliently urged outwardly by -leaf spring members 82 and. 84 which are located at various points within the doorsrsoas to. provide a substantially uniform force, holdingrthe panels 76 and 78against the flanges72 and74 when the doors tilland 62 are in the openpositiona When the doorsare closed, these .springshol d the panels 76 and 78 against the formed flat faced bead 86 which extends aroundthefront face of lthedoor jamb 88 immediately surroundingthe accessopening to the oven compartment 28,. vlPreferably,these panels are of 015" stainless steel .which readily conforms to any irregularities of the bead 86t .I l t' o ,a 4M V Thepanels76 and 78 are notronly mounted .so as to be movable-torwardlwand rearwardlybut they are also permittedlateral movement-by the flanges 72 and 74. The meetingedgesiot the panels .76 and 78 are providedv with-meeting flanges v 90 and-,. 92 which may. include stiffening -flangesr, 94 and; 96. Thegpanels 76-.and 78 are -resiliently urged toward each other... by the laterally acting leaf springs ,9 8 and l21.extending between the meeting flanges ,90 and 92 and the inturned .flanges 1 23 and .125, extending from the outer esheets 1274. 5111129 of the doors .60 and 62.. This insuresjthat the flanges 90 and 92 are held tightly in contact when thedoors are closed.

Preferably the doors are each pivotally connected to the links 131. These links 131 are preferably pivotally connected at their opposite ends to each other and to a traveler 133 which is slidably mounted in a horizontal guideway 135 beneath the oven liner 26. This linkand travele'r arrangement' insures that the; doors are closed simultaneously" and that-the openingof either door will cause the simultaneous opening of the other door;

To insure that-the faces of thepanels 76 and 78 are always aligned when the doors are closed as shownin Figure 3, the doors 60 and 62 are 'provided with the movable door handles 137-and 139 which are pivotally mounted upon the outer panels 127 and 129; An inwardly extending pin '141 is connected to the handle 137 and acorresponding; inwardly extending pin 14 3 is con nected to theihandle 139- These pins 141 and 143 are respectively adapted to engage the followers 145 and 147 which are fixed respectively to the panels- 76 and 78. The follower 145 is provided with 'a'projection 149 adapted to engage a projection 151 connected to the inner face of the outer panel- 127 so as to hold the inner'panel 76 from movement away fr'om'its hinged edge after it has been movedtoward the hinged edge by the engagement of the pins 141 with the-follower 145. In the opposite door the follower 147 is provided with a projection 153 which isfsimilarly adapted to' engage a corresponding projection 155 when the panel 78 is moved toward the hinges by the pin 143. IWhere the construction is such that the friction between the flanges 90 and 92 is small in the closing positions, the handle actuating system maybe omitted.

The purpose of this handle arrangement is to make use of the pull upon either of the handles 137 and 139 when the door is opened to hold the meeting flanges 90 and 92 apart until after the doors are closed. The panels 76 and 78 firmly engage the bead 86 and the springs 82 and 84 are compressed sufficiently to allow the projections 149 and 153 to pass outwardly of the projections 151 and 155 to free the panels 76 and 78 to permit the meeting faces 90 and 92 to move together under the force of the springs 98 and 121 as shown in Figure 3.

In Figure there is shown a modified form of the invention in which the doors 260 and 262 have inner panels 276 and 278 with concave and convex matching contacting flanges 290 and 292. These matching flanges 290 and 292 insurethe alignment of the panels 276 and 278 when the doors 260 and 262 are moved into closed position against the bead 85. These panels 276 and 278 are similarly pressed against the head 86 by the sets of springs 282 and 284. These panels 276 and 278 are also spring pressed toward the meeting edges by the laterally acting springs 298 and 321. These doors are provided with fixed handles 237 and 239 connected to their outer faces. They are also provided with flanges similar to the flanges 74 and 72. In all the door constructions, the inner panels float excepting for the restraint provided by the flanges 72'and 74 as well as the various springs and the followers 145 and 147.

The liner 26 and the door jamb particularly including the bead 86 are coated with porcelain enamel of the grade used for oven-liners. The porcelain coating upon the door jamb and the bead 86 further prevents or further minimizes any tendency to establish an arcing condition between the head 86 and the springy'stainless steel panels 76 and 78. The porcelain coating tends to form an effective electrical insulation barrier between the metal of the door jamb and the liner 26 and the tightly contacting metal panels 76 and 78. This are suppressing phenomena may be the result of the condenser-choke configuration formed by this design. The dielectric loss in the porcelain also tends to diminish to a negligible amount any electromagnetic radiation tending to escape between the bead 86 and the panels 76 and 78.

This arrangement isv also suitable when lit infra-red heating or convection heating is used in th oven in combination with the micro-wave heating apparatus. The doors 60 and 62 may be filled with glass meeting edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the'edges opposite said meeting edges to said walls, said doors each having inner movable panels and spring means for resiliently urging said panels into contact with said Walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panels having common meeting edges, said one door having spring means for resiliently'urging its panel toward the meeting edge of the panel of the adjacent door.

2. In combination, walls enclosing a compartment, said walls having an opening therein providing access to said compartment, a set of doors having common meeting edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the edges opposite said meeting edges to said walls, said doors each having inner movable panels and spring means for resiliently urging said panels into contact with said walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panel having common meeting edges, said one door having spring means for resiliently urging its panel toward the meeting edge of the panel of the adjacentdoor, and means for aligning the common meeting edges of said panels when the doors are closed.

3. In combination, walls enclosing a. compartment, said walls having an opening therein providing access to said compartment, a set of doors having common meeting edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the edges opposite said meeting edges to said walls, said doors each having inner movable panels and spring means for resiliently urging said panels into contact with said walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panel having common meeting edges, with matching surfaces, said one door having spring means for resiliently urging the panel toward the meeting edge of the panel of the adjacent door. V

4. In combination, walls enclosing a compartment, said walls having an opening therein providing access to said compartment, a set of doors having common meeting edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the edges opposite said meeting edges to said Walls, said doors each having inner movable panels and spring means for resiliently urging said panels into contact with said walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panels having common meeting edges, said one door having spring means for resiliently urging its panel toward'the meeting edge of the panel of the adjacent door, a handle for opening one of the doors, and means operated by said handle for moving the panel of one of the doors away from the common meeting edge.

5. In combination, walls enclosing a compartment, said walls having an opening therein providing access to said compartment, a set of doors having common meeting edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the edges opposite said meeting edges to said walls, said doors each having inner movable panels and spring means for resiliently urging said panels into contact with said walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panels having common meeting edges, said one door having spring means for resiliently urging its panel toward the meeting edge of the panel of the adjacent door, a handle for opening one of the doors, and means operated by said handle for moving the panel of one of the doors away from the common meeting edge, and stop means for holding the panel of one of the doors away from the common meeting edge when the handle is released.

6. In combination, walls enclosing a compartment, said walls having an opening therein providing access to said compartment, a set of doors having common meeting edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the edges opposite said meeting edges to said walls, said doors having inner movable panels and spring means for resiliently urging said panels into contact with said walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panels having common meeting edges, said one door having spring means for resiliently urging its panel toward the meeting edge of the panel of the adjacent door, a handle for opening one of the doors, and means operated by said handle for moving the panel of one of the doors away from the common meeting edge, and stop means for holding the panel of one of the doors away from the common meeting edge when the handle is released, said stop means being provided with a releasing arrangement operable coincidentally to the engagement of the walls around the access opening by the panel.

7. In combination, walls enclosing a compartment, said walls having an opening therein providing access to said compartment, a set of doors having common meet ing edges for closing said opening, pivotal connections pivotally connecting said doors adjacent the edges opposite said meeting edges to said walls, said doors each having inner movable panels and spring means for resiliently urging said panels into contact with said walls around said opening, one of said doors being provided with a lateral slideway for slidably supporting its panel, said panels having common meeting edges, said one door having spring means for resiliently urging its panel toward the meeting edge of the panel of the adjacent door, a handle for opening one of the doors, and means operated by said handle for moving the panel of one of the doors away from the common meeting edge, a laterally extending projection connected to and movable with said panel, a second projection located in the lateral path of movement of said laterally extending projection at the termination of the movement of the panel by the handle, said second projection having a recess for disengaging said projections when the panel is deflected upon engaging the portion of the walls surrounding the door opening.

References Cited in the file of this patent UNITED STATES PATENTS 2,566,578 Minor Sept. 4, 1951 2,644,989 Parkes July 14, 1953 2,748,239 Long et al. May 29, 1956 2,767,291 Ryckman Oct. 16, 1956 

